1. Field of the Invention
This invention relates to systems and methods for controlling the application of electronic circuits and, more particularly, to a temperature-actuated control circuit for shunting a fuel mixture enrichment circuit from a fuel delivery control circuit for internal combustion engines.
2. Description of the Prior Art
The requirement for increasingly reduced automobile emissions exacerbates problems such as cold starting, stalling and backfiring prior to engine warm-up, and the hazards inherent to entering and moving with traffic prior to engine warm-up. These problems are evident in many fuel injection systems, which frequently use computer-type circuits to control the fuel mixture and delivery. The problems can be alleviated by providing systems for altering the fuel delivery, typically by enrichening the fuel mixture.
Preferably, in view of the increasing cost and decreasing supply of gasoline, systems are also provided for inactuating or bypassing the fuel altering or enrichening systems after engine warm-up. Such systems may be based on dependency on external temperature variations or on time-delay characteristics. However, the prior art systems are relatively complex and are therefore more costly and more prone to failure than would be simpler systems.
As may be thus appreciated, it is desirable to have a simple, yet effective, and preferably, adjustable, automatic control circuit for controlling the operation, or connection to a fuel delivery control circuit, of a fuel enrichment circuit.